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M. DAVIS.

INTERNAL COMBUSTION ENGINE. APPLICATION FILED JUNE 5. 1916.

1,307, 1 86., latvnt-mi June 17, 191$).

I 1 D Q MERRILL DAVIS, 0F DETROIT, MICHIGAN.

INTERNALCOMBUSTION ENGINE.

' Specification of Letters Patent.

Patented June It, 191% Application filed June 5, 1916. Serial No. 101,758.

To all whom it may concern:

Be it known that I, MERRILL DAVIS, a citizen of the United States of America, residing at Detroit, in the county-of Wayne and State of Michigan, have invented certain new and useful Improvements in Internal-v Com'bustion Engines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to engine construction and in the particular embodiment of the invention shown in the drawings, I have shown it applied to that class of internal combustion engines, commonly known as the four-cycle or four-stroke, although in its broader aspects the invention is not limited to the particular use mentioned.

Among the objects of the invention are to provide a construction in which the burnt charge is completely displaced or forced out of the cylinder before the admission of another charge into that cylinder; toprovide a construction in which the efliciency of the engine is much greater than the engines in which there is no provision for positively expelling all of the burnt gases; to provide a construction in which the valve mechanism? that controls the inlet and exhaust to and from the cylinder can be utilized for obtaining the complete scavenging of the burnt gases; to so construct and arrange the parts that there will be sufficient space for the compressed gases just before the explosion stroke, this space, however, being filled by a part of the valve mechanism at the end of the exhaust stroke, and in general to provide a simple and eflicient construction of the character above referred to. The invention further resides in suchfeatures ofconstruction and arrangements and combinations of parts as will more fully hereinafter appear.

In the drawings:

Figure l is a vertical cross sectional viewthrough the cylinder of an engine to which my invention is applied;

Figs. 2, 3, 3* and 4: are similar fragmentar sectional views showing the parts in di erent positions of adjustment;

Figs. 5 and 6 are elevational views showing the drive mechanism for the valves.

Describing in detail the construction shown in the drawings, A designates the cylinder and B the piston longitudinally reciprocating within the cylinder. At the upper end the cylinder has a contracted axis of'the valve F extends transversely to the axis of the cylinder and the opposite sldes of the valve are recessed to provide concaved portions G and G located between alternate convex portions II and H. This valve fits within a valve casing J at one side of which there is an inlet opening K and the other side of which there is an exhaust port L. The valve may be driven from the crank shaft by various mechanisms but in the drawings I have shown a worm gear arrangement in which one half of the gear M is provided with spirally arranged teeth N which 'aduate into parallel form on the remaining half of the worm. As the engine shown is of the four-cycle type the gears O are of such size that they are driven at half the speed of the crank shaft, during the period in which the valve member is rotating. However the parallel arrangement of the teeth on one side of the driving gear or worm N will hold the valve from rotation part of the time.

The operation of the arrangement above described is as follows: With the parts in position shown in Fig. 1 the piston has just moved upward to the end of the compression stroke and is just starting the power stroke. The chamber formed by the concaved portion G of the valve and the concaved seat E of the piston is filled with compressed gas, which when ignited will force the piston downward until it reaches the position shown in Fig. 2. Here it has reached the end of the power stroke and is just beginning the exhaust stroke. The inclined teeth N of the gear M have at this point begun to rotate the gear 0 and thus turn the valve Funtil its concaved portion regis- 1 women has reached the end of its exhaust stroke the valve has been rotated to a position in which there is practically no clearance between. its convex surface H and the end of the piston, Thus the space is mechanically filled and there is a complete scavenging of all the burnt gases. As the pi ton starts down on the suction stroke the valve F continues to rotate and comll'llllllCdtlOIl is opened from the inlet port K to the explosion chamber through the concavcd portion G of the valve. As the piston moves down on the suction stroke it tends to create a vacuum in the explosion chamber which will draw a full charge of gas into the cylinder. Then when the piston has reached the end of its suction stroke and starts upward on the compression stroke, the driving gear N will have been moved to a position in which the parallel portion of the teeth engage with. the gear 0 and thus holds the valve from rotation during the entire compression and power strokes.

In order to facilitate the scavenging of the gases, I may in some instances, employ the arrangement shown only in Fig. l in which there is a Venturi tube Q located in the exhaust passage R and connected into the upper portion of the valve chamber J. By this arrangement, when the burnt gases rush out through the exhaust passage they will produce a suction on the tube S and tend to create a vacuum in the concaved chamber G so as to draw out any exhaust gases that may remain in this chamber.

Since the loss in efficiency in internal combustion engines, particularly of the four-cycle type, is generally due to inability to completely expel the burnt gases, which dilute and diminish the quantity of the incoming charge, it is obvious that an engine constructed in accordance with my invention is a material advancement in the art. I do not however desire to limit the invention entirely to internal combustion engines,

nor to any of the details of construction except as is specified in the appended claims.

What I claim as my invention is: 1. In an engine, the combination with a cylinder, of a piston reciprocating therein and having a concaved end, a valve mean I ber forming a part of the head of said cylinder and having a plurality of convex portions, each adapted in one position of adjustment to closely fit within the concaved end in the piston.

2. In an engine, the combination of a cylinder, a piston moving therein, of a valve chamber located at one end of said cylinder, said valvechamber having an inlet and an exhaust passage leading into it from approximately opposite sides, of a valve member disposed therein, said valve member having concave and convex sides disposed so as to be alternately brought into register with said cylinder, of a passage leading from said exhaust passage and terminating in top of said valve chamber at a point where one of the concave sides of said valve member will register therewith at the same time that another of the concave sides of said valve member is disposed inwardly in respect to said cylinder.

3. In an engine, the combination With a cylinder and a piston moving therein, of a rotatable member forming a part of the end of said cylinder, said rotatable member having alternately disposed concave and convex sides, and means for exhausting one of said concave sides while the other is in communication withthe cylinder.

4. In an engine, the combination with a cylinder and a piston moving therein, of a rotatable valve member forming a part of the end of said cylinder, said rotatable valve member having a plurality of concave portions, and means for exhausting one of said concave portions while the other is in communication with the cylinder In testimony whereof I affix my signature.

MERRILL DAVIS. 

